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Why is MP3 conversion causing pitch change???

Discussion in 'Converters / Interfaces' started by robchittum, Apr 20, 2003.

  1. robchittum

    robchittum Guest

    I recently converted some stuff done in Nuendo to MP3 "Pro" using Cool Edit Pro and it changed the pitch/tempo at various points in the song. Sounds like it slows down in the middle of the tune and then speeds up again before the end. Anybody got any ideas why this would happen and what I can do to fix it - this sucks?? Here's a link to the song if you want to hear what I'm talking about. I just posted the song for the guy that wrote it to hear the arrangement in progress - now I don't want him to.

    It does it on both songs that I converted but is most noticable on "used to be" Thanks for your thoughts.

    http://www.nowhereradio.com/artists/?aid=2852/singles

    Thanks,

    Rob
     
  2. Opus2000

    Opus2000 Well-Known Member

    Well, need some information on first how it was recorded.

    What sound card, what type of input, also sampling rate and bit depth.

    Also when mixed down in Nuendo to a final mix how was it done.

    For the Mp3, what kpbs settings did you use?

    Try and give us as much information as possible as that will be the only way to find the cause of this

    Opus :D
     
  3. robchittum

    robchittum Guest

    What sound card, what type of input, also sampling rate and bit depth.

    Was recorded first to Yamaha AW4416 at 16 bit 44k. Then transfered via RME digiset through lightpipe to Nuendo at same bit depth. The final mix was done by doing an Export to Mixdown as a wav. file. Then I opened the wave file in CEP and saved it as an MP3Pro file - then uploaded it. I tuned my guitar to the beginning of the MP3 post and it was in tune till about 53 seconds into the song where it lost pitch/tempo and then it comes back on pitch/tempo. However, I was tuned in standard tuning when I recorded it and it is not in standard at any point after the MP3 conversion. I checked it with the wav. mix that I did originally from Nuendo and it was dead on. So something is up with the CEP conversion for sure. Hope this added information helps figure out what the hell is going on with the conversion. Thanks a bunch for trying to help me figure it out.

    Rob
     
  4. Blutone

    Blutone Guest

    I might get blasted for this, but I think LAME is the best mp3 encoder out there. And, this is, IMHO, the best "free" converter going. I really recommend getting the Power Pack. It rocks.

    Here is a link to their site if ya wanna read about it first. :D

    Like the guy states on his site, the program is full on, uncrippled shareware. It has one pop-up that goes away when you register. If you can live with that, give this one a try. As always, I believe, if you like and use the program, then register the software. I'm sure many on this board would agree.

    WHEW! Enough already! HUH?!
    LOL
    Cheers,
    O
     
  5. Blutone

    Blutone Guest

    Oh, dbPoweramp also does Monkey Audio(lossless compression) too. :s:
     
  6. Opus2000

    Opus2000 Well-Known Member

    wierd...I'm not sure what could be the fault other than cool edit pro at this point.

    Doesn't Nuendo save as an MP3? Or am I high?!!!

    Opus :D
     
  7. Blutone

    Blutone Guest

    Umm...Yes...and...errrr...Yes :D
     
  8. robchittum

    robchittum Guest

    Dear "high" sirs, could you please tell me how I save as an MP3 from Nuendo? Can you do it in the audio export (mixdown)? Thank you - your "highness."

    Rob
     
  9. falkon2

    falkon2 Well-Known Member

    I've tried practically every encoder there is to try. LAME gives audibly better results. Think of D/A converters. Many of them "get the job done", but only good quality converters interpolate well to get a clean signal without any audible artefacts.

    In the same way, you'll want a utility that encodes with the best methods possible. Some encoders actually introduce high-end flanging and the like. LAME doesn't do any of this, and the algorithms it use give the best quality/bitrate ratio in any encoder so far. At the "insane" preset, the quality loss is probably less than or comparable to converting it to analog with top-of-the-line gear. A simple test would be to encode a .wav to .mp3, then import it with the phase inverted into a tracking program alongside the original .wav and play them both with unity gain. Whatever you hear is what's lost in the conversion.

    Now take a cheap-ass encoder bundled together with a program that's primary purpose is something other than MP3 encoding. You'll be surprised with the lossiness. Try out different bitrates for both encoders.


    Personally, I encode whatever I have to (for distribution over the net, mostly - I keep my backups and archives in lossless.ape, understandably) in alt preset standard using LAME. To me, its the best balance between quality and space. I support VBR (variable bit rate) as the way to go - LAME's algorithms calculate the number of bits required to represent the signal reasonably accurately.


    Oh, btw, the correct terminology:
    Encoding/Decoding - lossy formats, mp3, ogg, mpc, wma, etc.
    ;)

    I know not many people follow that, even official sources, but from a technical standpoint, those are the terms that SHOULD be used. ;)

    More good reads on .mp3 and other format encoding/compression by people who literally rip gigabytes of stuff:
    The Super-Guide of Audio Compression (MP3 and more)
    Guide to ripping the best MP3s!
     
  10. robchittum

    robchittum Guest

    I downloaded the dB conversion and it is indeed very cool. However, I cannot get my posts to play in hi fi stream. Any ideas as to why this would be?

    Thanks,

    Rob
     

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